Gigabyte GA-X48-DS4 + IDE channel configuration

Hi,

I've just bought a GA-X48-DS4 and am trying to boot from an IDE drive. When I look at the BIOS settings I see the drive come up as the master on channel 4, with nothing on any of the earlier channels. There's only one IDE socket on the motherboard... and currently I'm having difficulty booting the operating system because it can't find a root partition on the drive on such a high channel. Is there any way to reconfigure it so it shows up on channel 0?

Many thanks,

Michaël